The present invention relates to a bare chip carrier and a method of checking the bare chip by use of the same, and more particularly to an improved bare chip carrier suitable for automation and a method of checking the bare chip by use of the same.
For the bare chip test using a test carrier, it is required to realize an automation of connection and disconnection of a bare chip to the test carrier in order to reduce a manufacturing cost for a semiconductor device. Facilitation to the automation and highly accurate positioning due to further reduction in pitch of pads of the bare chip are important. Further, in order to improve the durability of the bare chip carrier, it is also important to realize a stable contact of the bare chip to the test carrier under a low pressure application.
FIG. 1 is a cross sectional elevation view illustrative of a first conventional test carrier to which a bare chip is connected. A carrier base 7 has a recessed portion in which an elastomer 8 is placed, thereby forming a flat top surface. A contact sheet 11 is placed on the flat top surface, wherein the contact sheet 11 has a top surface on which bumps 10 are provided. A bare chip 9 to be checked is placed on the bumps 10 and over the contact sheet 11, so that pads of the bare chip 9 are made into contact with the bumps 10. A carrier cap 1 is provided over the carrier base 7 and hinged to the carrier base 7. A pressing member 3 is also provided which is connected with an inner surface of the carrier cap 1 so that if the carrier cap 1 is made closed, then the pressure member 3 comes down to press the bare chip 9 downwardly for obtaining secure contacts between the pads of the bare chip 9 and the bumps 10 on the contact sheet 11 for carrying out the required check to the bare chip.
FIG. 2 is a cross sectional elevation view illustrative of a conventional mechanism of positioning the bare chip to the test carrier of FIG. 1. The positioning of the bare chip 9 to the test carrier is made with reference to external shapes of the bare chip 9 and a plate 16, for which reason a highly accurate dicing to the bare chip 9 is thus required. This makes it difficult to realize a further reduction in pitch of the pads of the bare chip 9.
Further, the pressing member 3 of FIG. 1 has a flat pressing surface for pressing the bare chip 9. If a degree of parallelization of the bare chip 9 to the flat pressing surface of the pressing member 3 is low, then the flat pressing surface of the pressing member 3 may be graded and made into contact with an edge portion of the bare chip 9. When the carrier cap 1 is made closed, then the bare chip 9 may be displaced or may be broken.
Furthermore, the pads of the bare chip 9 may be made into contact with the bumps 10 on the contact sheet 11 by the applied pressing force only. This makes it difficult to reduce the necessary pressing force for obtaining the required secure contact of the pads of the bare chip 9 to the bumps 10. The durability is thus deteriorated and it is difficult to reduce the manufacturing cost.
FIG. 3 is a fragmentary cross sectional elevation view illustrative of a second conventional test carrier developed by Texas Instruments/Micro-Module System. The positioning of the bare chip to the test carrier is made with reference to the external shape of the bare chip. The entire surface of the bare chip is pressed by the carrier cap. If a degree of parallelization of the bare chip to the pressing surface of the cap is low, then the pressing surface of the cap may be graded and made into contact with an edge portion of the bare chip. When the carrier cap is made closed, then the bare chip may be displaced or may be broken.
It is further required to rotate the carrier cap for opening and closing the cap. This is unsuitable for realizing the required automation. The cap is made of a metal whereby it is difficult to further reduce the cost.
In the above circumstances, it had been required to develop a novel bare chip carrier and a novel method of checking the bare chip by use of the same.
Accordingly, it is an object of the present invention to provide a novel bare chip carrier free from the above problems.
It is a further object of the present invention to provide a novel bare chip carrier suitable for realizing an automation.
It is a still further object of the present invention to provide a novel bare chip carrier which is inexpensive.
It is yet a further object of the present invention to provide a novel bare chip carrier free from any possibility of displacement of a bare chip in closing a cap of the bare chip carrier.
It is a further more object of the present invention to provide a novel bare chip carrier allowing a secure and stable contact of pads of the bare chip and bumps on a contact sheet of the bare chip carrier.
It is still more object of the present invention to provide a novel bare chip carrier allowing a reduction in applied pressing force to a bare chip for checking the bare chip.
It is moreover object of the present invention to provide a novel method of checking a bare chip carrier free from the above problems.
It is another object of the present invention to provide a novel method of checking a bare chip carrier suitable for realizing an automation.
It is still another object of the present invention to provide a novel method of checking a bare chip carrier which is inexpensive.
It is yet another object of the present invention to provide a novel method of checking a bare chip carrier free from any possibility of displacement of a bare chip in closing a cap of the bare chip carrier.
It is further another object of the present invention to provide a novel method of checking a bare chip carrier allowing a secure and stable contact of pads of the bare chip and bumps on a contact sheet of the bare chip carrier.
It is an additional object of the present invention to provide a novel method of checking a bare chip carrier allowing a reduction in applied pressing force to a bare chip for checking the bare chip.
The first present invention provides a bare chip carrier comprising: a carrier body having a base portion on which a bare chip is mounted and also having at least one cap holder; and a carrier cap having a pressing member for pressing the bare chip toward the base portion of the body, and the carrier cap being separated from the carrier body, wherein the at least one cap holder has at least a holder engagement portion which is to be engaged with a cap engagement portion of the carrier cap, so that the carrier cap separated from the carrier body is held by the at least one cap holder, whereby the bare chip is mounted by only a single operation of dropping the carrier cap onto the carrier body for realizing the automation.
The second present invention provides a bare chip carrier comprising: a carrier body having a base portion on which a bare chip is mounted and also having at least one cap holder; and a carrier cap having a pressing member for pressing the bare chip toward the base portion of the body, and the carrier cap being separated from the carrier body, wherein the carrier cap further has a spring member for applying a spring force to the pressing member toward the bare chip.
The third present invention provides a bare chip carrier comprising: a carrier body having a base portion on which a bare chip is mounted and also having at least one cap holder; and a carrier cap having a pressing member for pressing the bare chip toward the base portion of the body, and the carrier cap being separated from the carrier body, wherein the pressing member has at least one protruded contact portion which is to be made into contact with part of the bare chip so as to apply the pressing force through the at least one protruded contact portion to part of the bare chip for preventing an entire surface of the bare chip is pressed by the pressing member, for which reason the bare chip is free from any displacement due to deterioration of the degree of parallelization between the bare chip and the pressing surface of the pressing member of the test carrier.
The above and other objects, features and advantages of the present invention will be apparent from the following descriptions.